1. Field of the Invention
The present invention relates to a printer which prints in sequence on a print medium using a plurality of printer heads.
2. Description of the Related Art
Conventional printers of this type include, for example, a printer described in JP10-35021A. It comprises a plurality of printer heads each capable of printing a different color; and a transport portion which transports printing paper passing below the plurality of printer heads in sequence, wherein the plurality of printer heads print in sequence on the printing paper transported by the transport portion.
With such a printer, any meandering of printing paper during transport can distort a printed image. Thus, the printer described in JP10-35021A prints register marks on both edges of the printing paper during printing of a first color (during printing by the most upstream head), checks for meandering of the printed register marks during printing of second and subsequent colors (during printing by downstream heads), and thereby detects meandering of the printing paper. The printer moves the position of the printer heads as required based on the detected meandering so as to print each color in place, and thereby prevents distortion of the printed image.
However, with the conventional printer described above, since register marks are printed on the edges of the printing paper, it is not possible to print information on an entire surface of the printing paper. Consequently, to produce borderless prints, it is necessary to print the information on larger printing paper and then cut off the edges where the register marks are printed, involving great effort and expense.
To solve the outstanding problem with the conventional printer described above, the present invention has an object to provide a printer which can prevent distortion of printed images caused by meandering of printing paper and allows information to be printed on an entire surface of a print medium.